Question

Chicken Delight claims that 96% of its orders are delivered within 10 minutes of the time the order is placed. A sample of 70 orders revealed that 64 were delivered within the promised time. At the 0.01 significance level, can we conclude that less than 96% of the orders are delivered in less than 10 minutes?

(a) What is the decision rule? (Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.)
Reject Ho if z < ________

(b) Compute the value of the test statistic. (Negative amount should be indicated by a minus sign. Round the intermediate values and final answer to 2 decimal places.)
Value of the test statistic ________

Answer 1

Here using ti-83 calculator.

a)

Using z-table.

Alpha = 0.01

Reject H0 if z < -2.33

b)

Test statistic :-

z = -1.95

Do not reject the null hypothesis (H0).

Therefore, there is not enough evidence to conclude that

less than 96% of the orders are delivered in less than 10 minutes.